Tube rolling thread | UltraSonic Studios

[OctavianH]

I thought about your amp @Isaacc7 yesterday while reading about Philips 4682. You can also find a quad here, but I would say it's a little bit above what I would pay for it. However, these 4V heater tubes are very interesting. 4682 goes up to 375V on anode and can take around 10W dissipation. I guess might work in your amp. All these early 4V tubes are interesting to me. I guess a perfect amp for me would be 4V and 6.3V on output and 6.3V and 12.6V on input. Or variable input but I fear that amp, it would be too much for me because even this one is a challenge.

Ok, enough, let's go back to EL90. Mazda EL90 with Brimar 6SL7. This was a combo I was appreciating before EL50.

Coming from what I had on the amp last week it is quite a big difference. Less bass, separation, less natural sounding, less powerful, narrower. Well, many problems on many areas. But it is still enjoyable. I can listen to this. I have to get used with such differences because I doubt my top 3 will ever change again. So I'll need to appreciate also the "little" things. In this case the EL90.

PS. One thing about EL50 I have not mentioned. This one is not a pleasant one but we need to say also the cons. One of the tubes is problematic. When measuring them for 200V/20mA I had -14V and -15V so went aroudn -14.8V to be sure they stay in line. Because of gm, between them at the same grid bias I had around 4mA. Not very problematic since my output stage can work nicely from 15-24mA. So I have 9mA to accomodate not matched tubes. Of course, up to a limit. Well, I put my output stage current meter for the channel I put the "stronger" one and always considered the other 4mA lower. At startup I let stronger one go up to 23mA because in the first hour it decreases to 20-21mA (all tubes start to heat and after some time decrease in current). But from time to time, short periods, I heard distorsion in the channel where the weaker one was placed. At first I said, burn in? Distorsion was not noisy, a kind of high frequency roll-off. Muffled channel. But it was recovering. And for short periods, after long term operation. This made me think that the weaker one might go too low on current. So I checked this and voila, after a long session of listening my stronger one was around 21mA while the weaker one went to 14mA. Here we speak about 6-7mA between, almost double than what measured at startup. Why? Never saw something like this. Of course, there is an easy fix, when stronger one goes to 21mA after 1-2h of listening, you lower a little bit grid bias and put it back to 23mA then weaker one will be around 16-17mA. No problem. What interests me here is why one of the tubes behaves like this and the other not. Same tube, same construction. Measurements are in line for them. As I said, no big deal and worked perfectly for 1 week. I'll dig about this to see what can be the culprit. If one of my tubes is problematic is not a problem, if all EL50 might behave like this might be. Can be a problem on cathode bias where you just plug and play the tube and that's it? I have no idea, at least here I have control. This is why I like Eternity, it's perfect for people like me doing what I do.

 

[OctavianH]

Let's start the weekend in style. GEC A2900 with Mazda EL90. Some british warmness on top of the french flavour.

It's a fat sound, smooth and a little bit more than what I usually appreciate, but it's a good one for specific records.

PS. Reading of this afternoon: a guy builds an EL3N / EL50 (4654) amp and tries it for the first time. What he says here:

Re: 4654 Single-Ended Amplifier « Reply #32 on: May 11, 2017, 05:00:42 PM » ​ I had my first listen today: My first impression was - wow! Compared to my 1 W single-ended EL3N amplifier, it is a lot more dynamic, clear and more detailed. The stereo image is very much improved and the reverberation is better presented.

Yes mister, I hear you, I know what that "WOW" means. Been there.

PS2. Cool website here. Has some cool photos like for example for the 4654, but not only.

 

[OctavianH]

The big elephant in the room for me, related to small pentodes, was if EL81 still remains on the table. This was my start on the run towards EL81/82/83/84/85/90. Between these I've put also EL42 which was excellent and very unique, it still stands in my view as a very special tube. But later, as always, we went towards many others and in then end EL81 remained untouched. Where is EL81 today? This is what I tried to find out exchanging Mazda EL90 with Siemens EL81.

I left the GEC A2900 and tried to compare. Surprisingly Siemens EL81 which was for me the neutral reference one from all my EL81 sounds more powerful. Bass is stronger and soundstage an idea wider. Very good sound with GEC A2900, but the problem here is a little bit lack of energy because of lower amplification factor. And the tone is more towards "6SN7" than "6SL7" giving an idea of a less clean tone. Not very bad but well, we were used on EL90 with a quite clean presentation. Still, EL81 is very nice sounding and the bass and overall presentation keeps EL81 on the table. And this is with Siemens, we have the Mullard, Philips or Mazda 6DR6 here. A nice comparison would be between Mazda 6DR6 and Mazda EL90 and maybe one day I'll make it.

I'll need years to understand all these small pentodes, now I just try to see how I see the ones I've passed over after the latest discoveries and luckily for me EL81 still has a word to say. In 4-5 years I might be able to properly assess these. In my view EL81->85 have to be taken as a bunch, each one having it's own qualities, diversity and price being the success factor. I cannot say if EL90 is better than EL81. But I can say I have Mazda and Csf on EL90 and Siemens or Mullard on EL81 and all sound different. For more energy and a very clean tone I have the Telefunken EL803 (EL83). EL84 is too expensive, so I avoid it, even if I have 2 pairs made by WIRAG. EL82 and EL85 is nice because it provides a different flavour (Suresnes and Mitcham). All of them have something.

I would like to try Telefunken EL95. Maybe one day, who knows. Also to complete my view on early EL tubes with EL2, EL8 and so on. I am reading more and more about different EL3 and so on. It's like a puzzle and you discover more and more about it. The golden rule is to limit spending but in this area luckily nobody really cares. 90% of my bids were to 0 bid auctions. Audiophiles are on already expored roads and spend on very famous tubes. Excellent for me, a simple explorer not an audiophile.

Circling between all these will bring me a lot of fun without adding too many new ones on the table. My focus now is towards the history of tubes, making photos or learning how to identify. I already have my preferred combos, I already know what I like. But even if I put the best of the best on the amp, after 1 week I want to go back to the others. I could never live forever with one combination, but I can happily live with one amplifier: Eternity.

And a small remark about the size. Well I thought all these small pentodes are the same but well:

 

[triod750]

Variation of variety on Eternity .

 

[OctavianH]

Variation of variety on Eternity .

This is the polite way of telling that Eternity kills your time with style. Not bad because when I have too much time or lack of variety I spend money on other things than Jever. And we both know that is a wrong choice, except tubes.

Since it is Friday Beerday, I went to a famous monk.

Weißbier für alle.

 

[Isaacc7]

I thought about your amp @Isaacc7 yesterday while reading about Philips 4682. You can also find a quad here, but I would say it's a little bit above what I would pay for it. However, these 4V heater tubes are very interesting. 4682 goes up to 375V on anode and can take around 10W dissipation. I guess might work in your amp. All these early 4V tubes are interesting to me. I guess a perfect amp for me would be 4V and 6.3V on output and 6.3V and 12.6V on input. Or variable input but I fear that amp, it would be too much for me because even this one is a challenge.

Ok, enough, let's go back to EL90. Mazda EL90 with Brimar 6SL7. This was a combo I was appreciating before EL50.



Coming from what I had on the amp last week it is quite a big difference. Less bass, separation, less natural sounding, less powerful, narrower. Well, many problems on many areas. But it is still enjoyable. I can listen to this. I have to get used with such differences because I doubt my top 3 will ever change again. So I'll need to appreciate also the "little" things. In this case the EL90.

PS. One thing about EL50 I have not mentioned. This one is not a pleasant one but we need to say also the cons. One of the tubes is problematic. When measuring them for 200V/20mA I had -14V and -15V so went aroudn -14.8V to be sure they stay in line. Because of gm, between them at the same grid bias I had around 4mA. Not very problematic since my output stage can work nicely from 15-24mA. So I have 9mA to accomodate not matched tubes. Of course, up to a limit. Well, I put my output stage current meter for the channel I put the "stronger" one and always considered the other 4mA lower. At startup I let stronger one go up to 23mA because in the first hour it decreases to 20-21mA (all tubes start to heat and after some time decrease in current). But from time to time, short periods, I heard distorsion in the channel where the weaker one was placed. At first I said, burn in? Distorsion was not noisy, a kind of high frequency roll-off. Muffled channel. But it was recovering. And for short periods, after long term operation. This made me think that the weaker one might go too low on current. So I checked this and voila, after a long session of listening my stronger one was around 21mA while the weaker one went to 14mA. Here we speak about 6-7mA between, almost double than what measured at startup. Why? Never saw something like this. Of course, there is an easy fix, when stronger one goes to 21mA after 1-2h of listening, you lower a little bit grid bias and put it back to 23mA then weaker one will be around 16-17mA. No problem. What interests me here is why one of the tubes behaves like this and the other not. Same tube, same construction. Measurements are in line for them. As I said, no big deal and worked perfectly for 1 week. I'll dig about this to see what can be the culprit. If one of my tubes is problematic is not a problem, if all EL50 might behave like this might be. Can be a problem on cathode bias where you just plug and play the tube and that's it? I have no idea, at least here I have control. This is why I like Eternity, it's perfect for people like me doing what I do.

I am really trying to avoid buying more tubes and adapters. I have so so many now it is impossible to try them all. I own a handful of input tubes I haven‘t tried yet and 4 or 5 output tubes in the same situation. I’ve lost count of the possible combinations, I’ll never try them all. Not sure what the point would be because there’s no way that I can compare a combo I heard a year ago with the one I’m playing now. Trying new tubes is fun, trying new combos is fun but I have enough fun to last the rest of my life lol.

I’m actually in the process of putting aside a bunch of tubes that I will sell, hopefully all in one go. I won’t get nearly as much money that way but clearing out stuff I’ll never use is more important than maximizing the dollars. Most of them are only fit for DIY really. Things like the 6146 (and their 12v equivalent), 17dq6, etc. aren’t of much use to most folks. I’ll mix in some more mainstream tubes that are good/great to sweeten the deal.

 

[OctavianH]

I am really trying to avoid buying more tubes and adapters.

I'm in the same boat as you but I still like to explore one or two unknown types if I realize potential. Regarding adapters, I think more and more about a universal adapter which can be configured to accomodate all the tubes which use that socket. And for other sockets just to connect a socket adapter. Maybe I'll build it when I'll be old and then patent it. LOL

PS. Bought a pair of black glass EL90 so I'll soon add an eight pair to my comparison. I will check when receiving it if it's the same you tried.

 

[OctavianH]

I quite like the "industrial" design of these Siemens tubes and the sound signature matches it. The only problem here is that E88CC does not have enough gain for EL81, I would go here with 12AT7 or even 12AX7. In this combination I need to raise the volume above 50%. Of course I can go on my High Gain setting but I'll add some distortion.

 

[TheMiddleSky]

They released a HEDD Two! Why I have never saw anything about this? But it seems we have a thread.



This is what I'd call an interesting headphone. But 550g and 180g lighter than previous version.

Ah, I found why, who reads sponsor announcements. LOL

This one pick my interest too, but I'm also thinking about Tungsten. Decision, decision...

I'm not sure Oblivion suit the needs for low sensitivity and high impedance of Tungsten though.

 

[OctavianH]

This one pick my interest too, but I'm also thinking about Tungsten. Decision, decision...

I think it is too early to take such a decision. I thought about ordering one but delivery of 2nd batch of Heddphone Two will be in 31.10. To block those money 2 months instead of investing them is a bad choice. And I guess our fellow audiophiles will order and then put a few to classifieds for folks like us. Even in headphone choosing, like in tube rolling, patience is the key.

I'm not sure Oblivion suit the needs for low sensitivity and high impedance of Tungsten though.

I know a few used Oblivion with LCD-4. I doubt you will have problems.

Later edit: Now I found the numbers here for Tungsten. Hmm, 78.

Specifications
· Double-sided:
· Weight: 515g
· Impedance: 155 ohm average
· Sensitivity: 78 dB/mW average
· Single-sided:
· Weight 520g
· Impedance: 135 ohm average
· Sensitivity: 76db/mW

 

[OctavianH]

Being very intrigued by EL50, I've spent the last days trying to understand more about the differences between it and the metal base tubes. For that, I went to one or the other and tried to focus on 2-3 albums I know better. I usually listen to music without choosing specific tracks but in this case evaluation needed more preparation. Conclusion was that all the metal base tubes retain an analytical kind of sound and are more similar than different. I tried 4689 or 4654K with Fivre 6SL7 which I used extensively with EL50, then went for ITT Lorenz E88CC or Telefunken ECC801S. All outputs paired well with all of them, Fivre 6S7 being the most euphonic. I also made an 1:1 test between Fivre 6SL7 and Mullard ECC35 and for me, Fivre beats it by quite a margin. Both are warm, bold but Mullard ECC35 looses some detail and dynamics and adds a veil compared to Fivre 6SL7. So my favourite of all these Mullard ECC31-35 tubes remains the ECC33 and above all I'll put the Fivre 6SL7. It is not so bright yet keeps a decent level of transparency and dynamics without loosing sweetness. A very special tube for me. I have brown and black bases but never had time to investigate if the colour of the base influences sound. I doubt. I use the worse measuring one and it sounds perfect, by chance it's a brown base.

Below we have the Philips 4689 with Telefunken ECC801S. Maybe one of the most detailed and clean combinations I was able to hear on this amplifier. But even if I could not find a technical fault, I missed some sweetness and tube goodness some other combinations are providing. So even if you reach the top on a specific direction, you miss what other types of sound are offering you.

But now to the most interesting part. While 4654K and 4689 seem to me more variations of the same type of analytical sound, the EL50 remains very different from both of them. It's warmer but also more liquid without loosing the transparency and dynamics. And it has also a very good soundstage. It sounds very detailed and natural in the same time. While the metal base cousins keep a somehow dry and solid-state like sound because of their very technical presentation, EL50 remains very tubey but still competing very high on all the areas. You would consider it a winner? I avoid making such statements because this is very subjective. In this league there are no loosers or winners, just different presentations. Eternity being very neutral and detailed, might benefit more from a tubey technical presentation than other amplifier, therefore my praise to the tubey type of them. But this does not diminuate at all the value of the others. On a classical tube amp design, most probably, the more dry and technical ones make wonders and this is why all love them. In my case, well, I can easily live with EL50 (Philips 4654 ST shaped, grey glass red coated - I called it all this time EL50 to differentiate it from the rest).

 

[Isaacc7]

The dedicated threads for tube types have died down quite a bit. Makes me really appreciate how much of my tube buying was spurred on by everyone talking about them lol. I think most of the tube rolling talk is now on specific amplifier pages. Alas, think it’s mostly just you and I doing actual experiments here now.

As an update, I have been listening to the 5b/254m output tubes with c3m inputs. Those along with the Raytheon 12j5wgt in my preamp has given me a very accurate sound with a twinge of tube midrange warmth. Really nice.

I really like the Raytheon 12j5wgt. At one point they seemed to be pretty easy to get but supplies seem to have dried up. Finally found a seller with some in stock and bought him out. I have always been leery of running tubes I really like too much unless I have a good stock of them. The problem of needing 4 tubes at a time for input/preamp duties is that it only takes a problem with one tube to make the other 3 useless. I now have enough of the Raytheon tubes I don’t worry too much. I’d like to get more c3m tubes especially since they have the reputation of having really fragile heaters. I was hoping that the 5a/152m would be a good substitute but I think the gain is just a little too much to work as well.

I am closing in on my tube combos for life. Need to do some more experiments with the other el90 I have and revisit the 6v6ish tubes I have now that the el90 sounds so good. From this point onwards I’m hoping to not buy any more tube types and/or adapters. I will start the task of separating out the tubes I will use going forward and get rid of the rest. I will probably get some more 5b/254m, RCA 6bg6ga, and as I mentioned above some more c3m. Once I get those I will be set for input/preamp tubes with the 12j5wgt Raytheon, 12j5gt JAN Tung Sol, Cossor 6c5g, GEC l36, 14n7, and b36. I can use the 13d1 in the amp as well. I am undecided on the Tung Sol BGRP 12sn7. Outputs will probably be “limited” to the vt60a, 5b/254m, RCA 6bg6ga, Thompson 6005, Brimar 6aq5, maybe other 6aq5, and maybe some other 807 tubes.

 

[OctavianH]

The dedicated threads for tube types have died down quite a bit. Makes me really appreciate how much of my tube buying was spurred on by everyone talking about them lol. I think most of the tube rolling talk is now on specific amplifier pages. Alas, think it’s mostly just you and I doing actual experiments here now.

In my view those threads are for identification or internal construction. Sound related remarks are amp dependant anyway. Of course, up to a point, I recently see that other amp users share my experience on specific tube types.

As an update, I have been listening to the 5b/254m output tubes with c3m inputs.

I still have not decided to go towards these loctal tubes. I have a pair of C3g here but rarely using it.

Outputs will probably be “limited” to the vt60a, 5b/254m, RCA 6bg6ga, Thompson 6005, Brimar 6aq5, maybe other 6aq5, and maybe some other 807 tubes.

This sounds good, a part of them I also appreciate. I would still advise you to keep an eye on a quad of EL50. That is another animal than these. I also saw recently a lot of 6BQ6 quite cheap, maybe it's an alternative to me for 6BG6. No energy at the moment but who knows.

 

[Isaacc7]

In my view those threads are for identification or internal construction. Sound related remarks are amp dependant anyway. Of course, up to a point, I recently see that other amp users share my experience on specific tube types.

I still have not decided to go towards these loctal tubes. I have a pair of C3g here but rarely using it.

This sounds good, a part of them I also appreciate. I would still advise you to keep an eye on a quad of EL50. That is another animal than these. I also saw recently a lot of 6BQ6 quite cheap, maybe it's an alternative to me for 6BG6. No energy at the moment but who knows.

The c3m is a 20v tube so it would require a bit of an effort to use them in your amp. The c3o is the 6v equivalent but I think they have gotten hard to find and expensive. In any case, th Yeah have half the gain as the c3g. Hope I’m not repeating myself, I forget where I have posted this info before lol.

I’m sure the el50 is a great tube but I really don’t want to pursue another tube. Especially one with those horrid side contacts! More seriously, aren’t they related to the el34 in some way? Not sure how well they’d work with my 8k transformer.

If I were to look into another output tube seriously it would probably be the 6bq5/n78/6kg6 family of tubes. Those specify an 8k transformer. I am going to try a few more tubes that I already have along with their adapters but I don’t anticipate going all in on the gu50, 2e26, or 12av5.

 

[OctavianH]

The c3o is the 6v equivalent but I think they have gotten hard to find and expensive. In any case, th Yeah have half the gain as the c3g.

Indeed, now I see that C3o/m has different pinout than C3g and also 19 gain and 6.5 gm. But indeed, too expensive and I would not go towards it.

I’m sure the el50 is a great tube but I really don’t want to pursue another tube. Especially one with those horrid side contacts! More seriously, aren’t they related to the el34 in some way? Not sure how well they’d work with my 8k transformer.

That european base with side contacts is awful indeed. I cannot understand how they considered it a proper socket. For example, you cannot remove the tube without touching the glass. If you have an adapter like me you remove it from the amp and then try something, but if you have sockets on your amp like those, you drag the tube from the glass? Awful, I hate it, but the sound is too good to be able to ignore it so I got adapters and that's it. Not sure how much EL34 related, but some nice words here.